JP3506539B2 - Polypropylene resin composition and container using the composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene resin composition having excellent transparency and impact resistance, and a food product, daily sundries and medical use excellent in transparency and impact resistance using the composition. A highly transparent container suitable for, for example,

[0002]

2. Description of the Related Art Containers for foods such as pickled plums and pickles, and various daily sundries or medical infusion containers,
It is required to have good transparency so that the contents can be seen well, have excellent impact resistance, and have heat resistance so that cooking and sterilization can be performed. Conventionally, a random copolymer polypropylene resin having good transparency is often used for such applications, but it has a problem that the impact strength is not sufficient. In order to improve such a defect, mixing the random copolymer polypropylene resin with ethylene-propylene copolymer rubber (EPR), low density polyethylene (LDPE) or the like (see, for example, JP-A-58-11536, JP-A-52-72744 and JP-A-52-95759) have been carried out. However, such a composition has drawbacks such as a decrease in transparency and heat resistance. In order to solve these problems, mixing of ultra-low density linear polyethylene using Ziegler catalyst has been carried out, but in order to suppress the decrease in transparency and improve impact strength, low density linear polyethylene is mixed. There is a need. Linear polyethylene with low density has a low melting point, low heat resistance, high branching degree, low molecular weight components, and a large amount of elution into the content.These compositions have not been sufficiently and satisfactorily improved. . There is also a method of mixing linear low-density polyethylene having a high density in order to suppress heat resistance and decrease in elution components, but there is a drawback that transparency is deteriorated.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polypropylene resin composition having excellent transparency and impact resistance in order to meet these requirements. Another purpose is to use the above-mentioned composition, and the transparency is good so that the contents can be confirmed from the viewpoint of hygiene, etc., and the resin components are small so that the resin components do not migrate to the contents, and sterilization and cooking are performed. The object of the present invention is to provide a container having heat resistance sufficient to withstand boiling and having excellent impact resistance.
It is used as a container for daily sundries and medical items.

[0004]

Means for Solving the Problems The inventors of the present invention have made extensive studies in accordance with the above-mentioned object, and as a result, found that an ethylene polymer or an ethylene / α-olefin copolymer having a narrow molecular weight distribution or a narrow compositional distribution was added to a propylene-based polymer. By blending a nucleating agent and, if necessary, another ethylene polymer different from these, a polypropylene resin composition having excellent impact resistance while maintaining transparency and heat resistance is obtained, and by using it The present invention has been accomplished by finding that a container for foodstuffs, daily sundries, medical products, etc., which satisfies the above requirements, can be obtained.

That is, the present invention is, firstly, periodic table IV containing (A) a propylene-based polymer in an amount of 98 to 50% by weight and (B) (a) a ligand having a cyclopentadienyl skeleton.
(B) Density obtained by homopolymerizing ethylene or (co) polymerizing ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of a catalyst containing a group III transition metal compound as an essential component. 0.86-0.97g / c
m ³ , (c) Melt flow rate 0.1 to 50 g / 10
Min, (d) molecular weight distribution parameter Mw / Mn1.5-
5.0, (e) 2 to 50% by weight of an ethylene polymer or ethylene / α-olefin copolymer having a composition distribution parameter Cb of 1.2 or less, and (C) 0 to 48% by weight of another ethylene polymer. A polypropylene resin composition comprising 100 parts by weight of a resin component and 0.01 to 2 parts by weight of a (D) nucleating agent.

The present invention relates to (A) propylene polymer second
And a container made of the above polypropylene-based resin composition.

The present invention will be described in detail below. The (A) propylene polymer of the present invention is a polypropylene homopolymer, a block copolymer of propylene and α-olefin, a random copolymer of propylene and α-olefin, and the like. The copolymer is a copolymer of propylene and one or more α-olefins having 2 to 8 carbon atoms (excluding 3 carbon atoms), and particularly propylene / ethylene random copolymer, propylene / ethylene Ethylene / butene-1 random copolymers and propylene / butene-1 random copolymers are preferable because of their excellent transparency. Polypropylene homopolymers are used in applications where rigidity is required without giving much importance to transparency and impact resistance, and propylene-ethylene block copolymers are used with balance of impact resistance and rigidity without giving much importance to transparency. Used for required applications. The propylene-based polymer is a Ziegler
It is polymerized using a Natta type catalyst.

Among the above, in the propylene / ethylene random copolymer and the propylene / ethylene block copolymer, the content of ethylene and butene-1 in the copolymer is preferably 1 to 15% by weight, respectively. When the content of α-olefin is less than 1% by weight, the impact strength is not sufficient. Further, when the content of α-olefin exceeds 15% by weight, the rigidity is low and there is a possibility that it is not suitable as a container or the like.

The propylene polymer (A) of the present invention has a melt flow rate (MFR) of 0.1 to 70 g / 10 mi.
n, more preferably 0.5 to 60 g / 10 min. If the MFR is less than 0.1 g / 10 min, the fluidity is poor and molding becomes difficult. 70g / 1
If it exceeds 0 min, the impact strength is weak and it is unsuitable as a container. These MFRs may be prepared by thermally decomposing a polymerized polymer together with an organic peroxide.

The (B) ethylene polymer or ethylene / α-olefin copolymer of the present invention can be produced by the transition metal compound of Group IV of the periodic table containing the aforementioned (a) ligand having a cyclopentadienyl skeleton. And, optionally, in the presence of a catalyst containing a cocatalyst and an organoaluminum compound and / or a carrier, it is obtained by copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms. Further, the catalyst obtained by preliminarily polymerizing ethylene and / or the α-olefin with the above catalyst may be used as the catalyst.

The above α-olefin has 3 carbon atoms.
To 20, preferably 3 to 12, specifically propylene, butene-1, 4-methylpentene-1, hexene-1, octene-1, decene-1, dodecene-1.
And so on. The content of these α-olefins is usually selected in the range of 30 mol% or less, preferably 20 mol%.

A catalyst for producing the above-mentioned (B) ethylene polymer or ethylene / α-olefin copolymer of the present invention, (a) a ligand having a cyclopentadienyl skeleton, which belongs to Group IV of the periodic table. The cyclopentadienyl skeleton of the transition metal compound is a cyclopentadienyl group, a substituted cyclopentadienyl group or the like. As the substituted cyclopentadienyl group, a hydrocarbon group having 3 to 10 carbon atoms, a silyl group,
A substituted cyclopentadienyl group having at least one substituent selected from silyl-substituted alkyl group, silyl-substituted aryl group, cyano group, cyanoalkyl group, cyanoaryl group, halogen group, haloalkyl group, halosilyl group, etc. is there. The substituted cyclopentadienyl group may have two or more substituents, and the substituents may be bonded to each other to form a ring.

Examples of the hydrocarbon group having 1 to 10 carbon atoms include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group and the like. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group and isopropyl. Group, n-butyl group,
Alkyl groups such as isobutyl group, sec-butyl group, t-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group, decyl group; cycloalkyl groups such as cyclopentyl group, cycloalkyl group; phenyl group, tolyl group Examples thereof include aryl groups such as groups; aralkyl groups such as benzyl groups and neophyll groups. Of these, alkyl groups are preferred.

Preferred examples of the substituted cyclopentadienyl group include methylcyclopentadienyl group, ethylcyclopentadienyl group, n-hexylcyclopentadienyl group, 1,3-dimethylcyclopentadienyl group, 1,
3-n-butylmethylcyclopentadienyl group, 1,3
Specific examples thereof include -n-propylmethylethylcyclopentadienyl group. Among these, the substituted cyclopentadienyl group of the present invention is preferably a cyclopentadienyl group substituted with an alkyl group having 3 or more carbon atoms,
A 1,3-substituted cyclopentadienyl group is particularly preferable.

The substituted cyclopentadienyl group in the case where the substituents, ie, the hydrocarbons, are bonded to each other to form one or two or more rings, an indenyl group and a carbon number of 1 are used.
A substituted indenyl group, a naphthyl group, and a carbon number of 1 to 8 substituted with a substituent such as a hydrocarbon group (eg, an alkyl group) having 8 to 8 carbon atoms.
Preferred are a substituted naphthyl group substituted by a substituent such as a hydrocarbon group (alkyl group) and a substituted fluorenyl group substituted by a substituent such as a hydrocarbon group having 1 to 8 carbon atoms (alkyl group). It is mentioned as a thing.

Examples of the transition metal of the transition metal compound of group IV of the periodic table containing the above-mentioned (a) ligand having a cyclopentadienyl skeleton include zirconium, titanium and hafnium, and zirconium is particularly preferable.

The transition metal compound usually has 1 to 3 ligands having a cyclopentadienyl skeleton, and when they have 2 or more ligands, they may be bonded to each other by a bridging group. Examples of the cross-linking group include an alkylene group having 1 to 4 carbon atoms, an alkylsilanediyl group, and a silanediyl group.

As a ligand other than the ligand having a cyclopentadienyl skeleton in the transition metal compound of Group IV of the periodic table, hydrogen and C1 to C2 are typical.
And a hydrocarbon group of 0 (alkyl group, alkenyl group, aryl group, alkylaryl group, aralkyl group, polyenyl group, etc.), halogen, metaalkyl group, metaaryl group and the like.

Specific examples of these are as follows. As dialkyl metallocenes, bis (cyclopentadienyl) titanium dimethyl, bis (cyclopentadienyl) titanium diphenyl, bis (cyclopentadienyl) zirconium dimethyl, bis (cyclopentadienyl) zirconium diphenyl, bis (cyclopentadienyl) ) Hafnium dimethyl, bis (cyclopentadienyl) hafnium diphenyl and the like. Monoalkyl metallocenes include bis (cyclopentadienyl)
Examples include titanium methyl chloride, bis (cyclopentadienyl) titanium phenyl chloride, bis (cyclopentadienyl) zirconium methyl chloride, and bis (cyclopentadienyl) zirconium phenyl chloride.

Further examples include monocyclopentadienyl titanocene such as pentamethylcyclopentadienyl titanium trichloride, pentaethylcyclopentadienyl titanium trichloride, and bis (pentamethylcyclopentadienyl) titanium diphenyl.

Examples of the substituted bis (cyclopentadienyl) titanium compound include bis (indenyl) titanium diphenyl or dichloride, bis (methylcyclopentadienyl) titanium diphenyl or dichloride, dialkyl, trialkyl, tetraalkyl, and pentaalkylcyclo. Examples of the pentadienyl titanium compound include bis (1,2-dimethylcyclopentadienyl) titanium diphenyl or dichloride, bis (1,2-diethylcyclopentadienyl) titanium diphenyl or dichloride or other dihalide complex, silicon, amine Alternatively, as the carbon-linked cyclopentadiene complex, dimethylsilyldicyclopentadienyl titanium diphenyl or dichloride, methylenedicyclopentadienyl complex Data iodonium diphenyl or dichloride, and other dihalide complexes.

As the zirconocene compound, pentamethylcyclopentadienyl zirconium trichloride,
Pentaethylcyclopentadienyl zirconium trichloride, bis (pentamethylcyclopentadienyl)
Examples of zirconium diphenyl and alkyl-substituted cyclopentadiene include bis (ethylcyclopentadienyl) zirconium dimethyl, bis (methylcyclopentadienyl) zirconium dimethyl, bis (n-butylcyclopentadienyl) zirconium dimethyl, haloalkyl or dihalide thereof. As the complex, dialkyl, trialkyl, tetraalkyl or pentaalkylcyclopentadiene, bis (pentamethylcyclopentadienyl) zirconium dimethyl, bis (1,2-dimethylcyclopentadienyl) zirconium dimethyl, and dihalide complexes thereof, silicon As the carbon-linked cyclopentadiene complex, dimethylsilyldicyclopentadienylzirconium dimethyl or dihalide, methylenedicyclopentene Dienyl zirconium dimethyl or dihalide, such as methylene dicyclopentadienyl zirconium dimethyl or dihalide, and the like.

Still other metallocenes include bis (cyclopentadienyl) hafnium dichloride, bis (cyclopentadienyl) hafnium dimethyl, bis (cyclopentadienyl) vanadium dichloride and the like.

As another example of the transition metal compound of Group IV of the periodic table of the present invention, a ligand having a cyclopentadienyl skeleton represented by the following general formula and other ligands and transition metal atoms are The thing which forms a ring is also mentioned.

[0025]

[Formula 1]

In the formula, Cp is a ligand having the cyclopentadienyl skeleton, X is hydrogen, halogen, and having 1 to 2 carbon atoms.
0 represents an alkyl group, an arylsilyl group, an aryloxy group, an alkoxy group, an amido group, a silyloxy group, etc., and Y represents —O—, —S—, —NR—, —PR— or O.
A divalent neutral ligand selected from the group consisting of R, SR, NR ₂ , and PR ₂ , Z is SiR ₂ , CR ₂ , SiR ₂ SiR
₂ , CR ₂ CR ₂ , CR = CR, SiR ₂ CR ₂ , BR
₂ represents a divalent group selected from the group consisting of BR. However, R is hydrogen or an alkyl group having 1 to 20 carbon atoms, an aryl group, a silyl group, a halogenated alkyl group, a halogenated aryl group, or Y, Z or 2 from both Y and Z.
The one or more R groups are those that form a fused ring system. M represents a transition metal atom of Group IV of the periodic table.

As an example of the compound represented by the formula 1, (t
-Butylamido) (tetramethylcyclopentadienyl) -1,2-ethanediyl zirconium dichloride, (t-butylamido) (tetramethylcyclopentadienyl) -1,2-ethanediyl titanium dichloride, (methylamido) (tetramethyl Cyclopentadienyl) -1,2-ethanediyl zirconium dichloride, (methylamido) (tetramethylcyclopentadienyl) -1,2-ethanediyl titanium dichloride,
(Ethylamide) (tetramethylcyclopentadienyl) methylenetan dichloride, (t-butylamide)
Dimethyl (tetramethylcyclopentadienyl) silane titanium dichloride, (t-butylamido) dimethyl (tetramethylcyclopentadienyl) silane zirconium dibenzyl, (benzylamido) dimethyl (tetramethylcyclopentadienyl) silane titanium dichloride, ( Phenylphosphide) dimethyl (tetramethylcyclopentadienyl) silane titanium dichloride and the like.

The cocatalyst referred to in the present invention can effectively use the above-mentioned transition metal compound of Group IV of the periodic table as a polymerization catalyst, or can balance the ionic charge in a catalytically activated state. Say.

Examples of the cocatalyst used in the present invention include benzene-soluble aluminoxanes of organoaluminum oxy compounds, organoaluminum oxy compounds insoluble in benzene, boron compounds, lanthanoid salts such as lanthanum oxide, tin oxide and the like. Of these, aluminoxane is most preferable.

The catalyst may be used by supporting it on a carrier of an inorganic or organic compound. The carrier is preferably a porous oxide of an inorganic or organic compound, specifically S
iO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B
₂ O ₃ , CaO, ZnO, BaO, ThO _2, etc. or a mixture thereof can be mentioned, and SiO ₂ —Al ₂ O ₃ , Si
_{O 2 -V 2 O 5, SiO} 2 -TiO 2, SiO 2 -Mg
_O, like SiO 2 _-Cr 2 _{O 3} and the like.

Examples of the organic aluminum compound include trialkyl aluminum such as triethyl aluminum and triisopropyl aluminum; dialkyl aluminum halide; alkyl aluminum sesquihalide; alkyl aluminum dihalide; alkyl aluminum hydride and organic aluminum alkoxide.

The process (B) for producing an ethylene polymer or an ethylene / α-olefin copolymer of the present invention is carried out in the presence of the above-mentioned catalyst, in the absence of a solvent, in a gas phase polymerization method, a slurry polymerization method, a solution polymerization method. Manufactured by legal method, etc., substantially oxygen,
Illustrated as an aliphatic hydrocarbon such as butane, pentane, hexane, and heptane, an aromatic hydrocarbon such as benzene, toluene, and xylene, and an alicyclic hydrocarbon such as cyclohexane and methylcyclohexane in a state where water and the like are turned off. It is produced in the presence or absence of an inert hydrocarbon solvent. The polymerization conditions are not particularly limited, but the polymerization temperature is usually 15 to 35.
0 ° C, preferably 20 to 200 ° C, more preferably 5
The polymerization pressure is usually from normal pressure to 70 kg / cm ² G, preferably from normal pressure to 20 kg / in the case of the low and medium pressure method.
cm ² G, usually 1500 kg / cm for high pressure method
² G or less is desirable. Polymerization time is usually 3 for low and medium pressure method
Minutes to 10 hours, preferably 5 minutes to 5 hours is desirable. In the case of the high pressure method, it is usually 1 minute to 30 minutes, preferably 2 minutes to 20 minutes. The polymerization is not limited to the one-step polymerization method, and is not particularly limited to a two-step or more multi-step polymerization method in which the polymerization conditions such as hydrogen concentration, monomer concentration, polymerization pressure, polymerization temperature and catalyst are different from each other.

Specific (B) of the present invention obtained with the above catalyst
Ethylene polymers or ethylene / α-olefin copolymers have different properties from those of ethylene / α-olefin copolymers obtained by conventional Ziegler-type catalysts and Phillips-type catalysts (collectively referred to as Ziegler-type catalysts). It is a thing. That is, the specially-prepared (B) ethylene polymer or ethylene / α-olefin copolymer of the present invention obtained with the above catalyst has a narrow molecular weight distribution and a narrow composition distribution because the active sites of the catalyst are uniform. It will be. For this reason, it has high transparency and strength, and since there are few components with a very large amount of short chain branching and low molecular weight components, there is little bleeding out on the resin surface. Strength is improved. Especially, 2 to 30% by weight is used for applications requiring a balance of transparency and impact resistance with little decrease in transparency, and 30 to 50% by weight is used for applications where importance is attached to impact resistance. To be

The ethylene polymer or ethylene.α-
The density (b) of the olefin copolymer (B) is 0.86 to
0.97 g / cm ³ , preferably 0.89 to 0.94 g
/ Cm ³ range, and below 0.86 g / cm ³ ,
Low flexural modulus, impaired heat resistance, 0.97 g / c
If it exceeds m ³ , impact resistance may be impaired. Further, (c) the melt flow rate is 0.01 to 50.
g / min, preferably 0.1 to 20 g / min, more preferably 0.5 to 10 g / 10 min. Also (d)
The width Mw / Mn of the molecular weight distribution is in the range of 1.5 to 5.0, preferably 1.8 to 4.5. Mw / Mn is 1.
If it is less than 5, the workability becomes poor, and if it exceeds 5.0, the effect of improving the impact strength is small. Further, the (e) composition distribution parameter (Cb), which is a scale showing the breadth of the composition distribution, is 1.2 or less. If this value exceeds 1.2, the effect of improving transparency and strength is poor.

The ethylene polymer or ethylene.
The method for measuring the composition distribution parameter (Cb) of the α-olefin copolymer (B) is as follows. That is, the sample was heated and dissolved at 135 ° C. in an ODCB solvent containing an antioxidant so as to have a concentration of 0.2% by weight, and then transferred to a column packed with diatomaceous earth (Celite 545).
Cool to 25 ° C. at a cooling rate of 0.1 ° C./min to deposit the copolymer sample on the Celite surface. Next, while the ODCB is caused to flow through the column in which this sample is deposited at a constant flow rate, the column temperature is gradually raised to 120 ° C. in steps of 5 ° C. Then, a solution containing the eluted components corresponding to each temperature is collected. Methanol is added to this solution to precipitate a sample, which is then filtered and dried to obtain an elution sample at each temperature. Weight fraction and degree of branching (C 1000
The number of branches per piece) is measured. Branching degree (measured value) is 1
Measured and determined by 3C-NMR.

For each of the fractions collected at 30 ° C. to 90 ° C. by the above method, the branching degree is corrected as follows. That is, the degree of branching measured against the elution temperature is plotted, and the correlation is approximated to a straight line by the method of least squares,
Create a calibration curve. The correlation coefficient of this approximation is sufficiently large.
The value obtained from this calibration curve is the branching degree of each fraction. This correction is not performed for the fractions collected at an elution temperature of 95 ° C or higher, because the elution temperature and the degree of branching do not always have a linear relationship.

Next, the weight fraction w of each fraction
_i is the amount of change in the branching degree b i per elution temperature of 5 ° C. (b _i
-B _i-1 ) to obtain the relative concentration C _i , and plot the relative concentration against the branching degree to obtain a composition distribution curve. This composition distribution curve is divided by a certain width, and the composition distribution parameter Cb is calculated by the following formula.

[0038]

[Formula 2]

Here, C _i and b _i are the relative density and branching degree of the j-th section, respectively. Composition distribution parameter C
b becomes 1.0 when the composition of the sample is uniform, and increases as the composition distribution spreads.

Many proposals have been made for the method of expressing the composition distribution of the ethylene / α-olefin copolymer. For example, in JP-A-60-88016, numerical processing is performed assuming that the cumulative weight fraction has a specific distribution (logarithmic normal distribution) with respect to the number of branches of each fractionated sample obtained by solvent fractionation of the sample, The ratio between the weight average branching degree (Cw) and the number average branching degree (Cn) is determined. The accuracy of this approximate calculation is low when the number of branches of the sample and the cumulative weight fraction deviate from the lognormal distribution, and the correlation coefficient R ² is considerably low when the measurement is performed on commercially available LLDPE, and the accuracy of the value is not sufficient. The Cw / Cn measuring method and the numerical processing method are the same as those of the present invention.
Although it is different from that of b, if you dare to compare the numerical values, Cw
The value of / Cn becomes considerably larger than Cb.

The other ethylene-based polymer (C) of the present invention is
Improves the impact strength of component (A) together with component (B). If (A) + (B) + (C) is 100% by weight, 48% by weight or less of all the resin components are mixed if necessary. To be done. If the content of (B) is less than 2% by weight, there will be no polypropylene modifying effect and the mechanical properties will be poor, and if it exceeds 50% by weight, the rigidity will be too low. On the other hand, when the content of the component (C) exceeds 48% by weight, the properties of polypropylene become poor and the rigidity becomes too low.

The ethylene polymer or ethylene / α-olefin copolymer (C1), which is one of the components (C1), using a Ziegler catalyst having a density of 0.86 to 0.97 g / cm ³ is prepared by a conventional ionic polymerization method. In addition to the so-called Ziegler type catalyst, it is a polymer to be polymerized and also includes a copolymer polymerized by a Phillips catalyst. Specifically, high density polyethylene (HDPE), linear medium density polyethylene (MDPE), linear Low density polyethylene (LLDP
E), ultra low density polyethylene (VLDPE) and the like.

High Density Polyethylene (HDPE) of the Invention
Has a density of 0.95 to 0.97 g / cm ³ , and linear medium-low density polyethylene (MDPE, LLDPE)
The density is 0.91 to 0.95 g / cm ³ , preferably 0.1.
The range is 91 to 0.94 g / cm ³ (LLDPE), and the MFR is 0.1 to 20 g / 10 min, preferably 0.5 to 15 g / 10 min, and more preferably 0.7.
It is selected within the range of -10 g / 10 min. Melt tension is 0.3 to 15.0 g, preferably 0.4 to 8.0 g. More preferably, it is 0.5 to 7.5 g. Mw / Mn is 2.5-5, preferably 3-4.5.

The ultra low density polyethylene (VLDP of the present invention
E) means that the density is 0.86 to less than 0.91 g / cm ³ ,
Preferably 0.88 to 0.905 g / cm ³ , MFR 0.1 to 20 g / 10 min, preferably 0.5 to 10
It is selected within the range of g / 10 min. The ultra-low density polyethylene (VLDPE) has a polyethylene having an intermediate property between linear low-density polyethylene (LLDPE) and ethylene / α-olefin copolymer rubber (EPR, EPDM), and has a differential scanning calorie. A specific ethylene / α-olefin copolymer having a maximum peak temperature (Tm) of 60 ° C. or more by a measuring method (DSC) and a boiling n-hexane insoluble content of 10% by weight or more, at least titanium and / or vanadium. Polymerized using a catalyst consisting of a solid catalyst component containing an organoaluminum compound and having a high crystalline portion represented by a linear low-density polyethylene and an amorphous portion represented by an ethylene / α-olefin copolymer rubber. As a resin, the former features such as mechanical strength and heat resistance, and the latter features such as rubber elasticity and low temperature impact resistance. Such as co-exist well-balanced.

The α-olefin of the above-mentioned (C1) ethylene / α-olefin copolymer has a carbon number of 3 to 12, preferably 3 to 10, specifically, propylene, butene-1, 4 -Methylpentene-1, hexene-
1, octene-1, decene-1, dodecene-1 and the like. The content of these α-olefins is 40
It is preferably selected in the range of mol%.

The second component C of the present invention is (C2) low density polyethylene by high pressure radical polymerization, ethylene / vinyl ester copolymer, copolymer with ethylene / α, β-unsaturated carboxylic acid or its derivative. Is.

The above low density polyethylene (LDPE) is
MFR (melt flow rate) is 0.1-20g / 10
min, preferably 0.5 to 15 g / 10 min, more preferably 1.0 to 10 g / 10 min. Within this range, the melt tension of the composition will be in an appropriate range, and in the case of a film or sheet, molding will be easy. The density is 0.91 to 0.94 g / cm ³ , preferably 0.912.
To 0.935 g / cm ³ , more preferably 0.912
˜0.930 g / cm ³ , and the melt tension is 1.5 to 2
5 g, preferably 3 to 20 g, more preferably 3 to 1
It is 5 g. Further, Mw / Mn is 3.0 to 10, preferably 4.0 to 8.0.

The ethylene / vinyl ester copolymer of the present invention means vinyl propionate, vinyl acetate, vinyl caproate, vinyl caprylate, vinyl laurate, stearin produced by a high pressure radical polymerization method and containing ethylene as a main component. It is a copolymer with vinyl ester monomers such as vinyl acrylate and vinyl trifluoroacetate. Of these, vinyl acetate is particularly preferable. That is, a copolymer composed of 50 to 99.5% by weight of ethylene, 0.5 to 50% by weight of a vinyl ester, and 0 to 49.5% by weight of another copolymerizable unsaturated monomer is preferable. Particularly, the vinyl ester content is in the range of 3 to 20% by weight, preferably 5 to 15% by weight.

The MFR of these copolymers is 0.1 to 20.
g / 10 min, preferably 0.3 to 10 g / 10 mi
n, and the melt tension is 2.0 to 25 g, preferably 3 to
It is 20 g.

Typical examples of the copolymer of ethylene of the present invention with α, β-unsaturated carboxylic acid or its derivative include ethylene / (meth) acrylic acid or its alkyl ester copolymer. Examples of these comonomers include acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, isopropyl methacrylate, acrylic acid-n. -Butyl, methacrylic acid-n-
Butyl, cyclohexyl acrylate, cyclohexyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate,
Examples thereof include glycidyl acrylate and glycidyl methacrylate. Among these, alkyl esters of (meth) acrylic acid such as methyl and ethyl are particularly preferable. In particular, the (meth) acrylic acid ester content is in the range of 3 to 20% by weight, preferably 5 to 15% by weight.

The MFR of these copolymers is 0.1 to 20.
g / 10 min, preferably 0.3 to 10 g / 10 mi
n, and the melt tension is 2.0 to 25 g, preferably 3 to
It is 20 g.

The term (D) nucleating agent as used in the present invention is used as a nucleating agent for polyolefin to improve transparency, rigidity and the like. In the present invention, sorbitol is used.
A compound or aromatic phosphate compound
Be done.

Examples of the sorbitol compound include dibenzylidene sorbitol, 1,3,2,4-di (methylbenzylidene) sorbitol, 1,3,2,4- (ethylbenzylidene) sorbitol, 1,3,2,4- ( Methoxybenzylidene) sorbitol, 1,3,2,4-
(Ethoxybenzylidene) sorbitol and the like can be mentioned.

[0054]

As the nucleating agent in the present invention , an aromatic phosphoric acid ester compound is most preferably used because it has little odor.

The aromatic phosphoric acid ester compound specifically has a structure represented by the following general formula (Formulas 2 to 8).

[0057]

[Formula 3]

(In the formula, R ₁ and R ₂ represent a hydrogen atom or an alkyl group having 1 to 9 carbon atoms, and M ₁ represents a metal atom of Group I of the periodic table.)

[0059]

[Formula 4]

(In the formula, R ₃ and R ₄ represent a hydrogen atom or an alkyl group having 1 to 9 carbon atoms, R ₅ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and M ₂ is a periodic table. In the table, metal atoms of Group I, Group II, and Group III are shown, and a shows the valence of M _2. )

[0061]

[Formula 5]

(In the formula, R ₆ is a hydrogen atom or a carbon number of 1 to
4 is an alkyl group, and R ₇ and R ₈ are each a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group. )

[0063]

[Formula 6]

(In the formula, X represents a direct bond, an alkylene group or an alkylidene group, and R ₉ , R ₁₀ , R ₁₁ and R
₁₂ and R ₁₃ are each a hydrogen atom or a carbon number of 1 to 1.
2 represents an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group. A represents an ammonium ion or an organic ammonium ion, and m and n each represent 1 to 6. )

[0065]

[Formula 7]

(In the formula, R ₁₄ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ₁₅ and R ₁₆ represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms,
M ₃ represents a metal atom of Group III or IV of the Periodic Table, Y represents an —OH group when M ₃ is Group III of the Periodic Table, M
_{When 3} is Group IV of the periodic table, OH group and-(OH) ₂
Indicates a group. )

[0067]

[Formula 8]

(In the formula, R ₁₇ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ₁₈ and R _{19 each} represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group, Represents an aralkyl group, and Z is-
OH group or ^-O - shows the _NH ^{4 +} group. )

Typical examples of commercially available aromatic phosphate ester compounds represented by Chemical Formulas 2 to 8 are:
Asahi Denka Kogyo Co., Ltd. product name MARK NA-10, MA
Examples thereof include RKNA-11 and MARK NA-21, which may be used alone or in admixture of two or more.

The amount of these nucleating agents added is 100% by weight of the resin mixture.
0.01 to 2 parts by weight, preferably 0.0
3 to 1 part by weight. If the amount is less than 0.01 parts by weight, the transparency is not sufficiently improved, and if the amount is more than 2 parts by weight, the effect is not changed despite the increase in the addition amount, which is uneconomical and has a bad odor.

The container in the present invention is a highly transparent container which is molded from the above composition and is excellent in impact resistance and the like. For example, food containers such as food products such as pickled plums, pickles and confectionery, Daily miscellaneous goods containers such as clothing and office supplies,
It is used for medical containers such as blood transfusion and infusion containers and syringes. The method for molding the container is not particularly limited, and is most preferably injection molding, such as injection molding, extrusion molding, blow molding, and sheet molding.

In the present invention, a lubricant, an antistatic agent, an antifogging agent, a pigment, an ultraviolet absorber, a dispersant, as well as an antioxidant may be used, if necessary, within a range that does not essentially impair the characteristics of the invention. Known additives such as acid absorbers can be added.

[0073]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention. The test method used in this example is as follows.

[0074] (Physical property test method) Polypropylene and composition   MFR: Based on JIS K6758.   Flexural modulus: According to ASTM D790.   Izod impact test: Based on JIS K6758.   DuPont impact test: Toyo Seiki injection-molding test pieces with a thickness of 2 mm and a diameter of 50 mm                         It was measured with a DuPont impact tester manufactured by Kikai Co., Ltd.   Haze: A test piece with a thickness of 2 mm and a diameter of 50 mm is injection-molded according to JIS                           Direct reading haze computer according to K7105 regulations                         (Product name: HGH-2DP, manufactured by Suga Test Instruments Co., Ltd.)                         The measured haze is shown.   Heat resistant note (heat distortion temperature): Based on JIS K7207.   Odor: The composition was smelled and examined.                         ○: No odor                         △: Slight odor Ethylene / α-olefin copolymer   Density: Based on JIS K6760.   MFR: Based on JIS K6760.   Mw / Mn: GPC Waters Model 150                         Solvent: ODCB 135 ° C                         Column: GMM HR-H (S) manufactured by Tosoh Corporation                         Calibration curve: According to PS standard sample.

[0075] (Molding conditions by injection molding machine)   Injection molding machine: Japan Steel Works, Ltd. JSW100 Mold clamping force 100TON   Molding resin temperature: 220 ℃   Cushion molding   Mold temperature: 50 ℃

The components used are as follows. (A) Polypropylene (A1) Propylene / ethylene random copolymer (RP
PFR) MFR: 32 g / 10 min. , Ethylene content: 4.
3% by weight (A2) propylene homopolymer (referred to as HPP) MFR: 30 g / 10 min. (A3) Propylene / ethylene block copolymer (BP
Referred to as P) MFR: 45 g / 10 min. , Ethylene content: 7.
7% by weight

(B) Ethylene / α-olefin copolymer (B1 to B3) Polymerization was carried out by the following method. <Polymerization of ethylene / α-olefin copolymer> 1) Polymerization of ethylene / butene-1 copolymer (B1, B2) A stainless steel autoclave equipped with a stirrer was replaced with nitrogen and purified toluene was put therein. Then, butene-1 was added, and bis (n-butylcyclopentadienyl) zirconium dichloride (0.02 mmol as Zr) methylalumoxane [MAO] (MAO / Zr = 500).
After the mixed solution of [molar ratio]) was added, the temperature was raised to 80 ° C. Next, ethylene was added to initiate polymerization. Polymerization was carried out for 1 hour while maintaining the total pressure while continuously polymerizing ethylene. In addition, these polymerizations were repeated and produced in an amount necessary for Examples described later. The physical properties of the obtained ethylene / butene-1 copolymer were as follows.

2) Polymerization of ethylene / octene-1 (B3) copolymer A stainless steel autoclave equipped with a stirrer was replaced with nitrogen and purified toluene was added. Then octene-1 was added and heated to 140 ° C. Next, ethylene was added thereto and then dissolved in toluene (tert-butylamido) dimethyl (tetramethylcyclopentadienyl) silane zirconium dichloride (0.02 mmol as Zr).
Methylalumoxane [MAO] (MAO / Zr = 500
[Molar ratio]) mixed solution was added. Polymerization was stopped after 15 minutes to obtain a polymer. In addition, these polymerizations were repeated and produced in an amount necessary for Examples described later. The physical properties of the obtained ethylene / octene-1 copolymer were as follows. MFR: 2,0 g / 10 min Density: 0.920 g / cm ³ Molecular weight distribution (Mw / Mn): 2.4 Cb: 1.04

(C) Other ethylene-based (co) polymer (C1) Low-density linear polyethylene (referred to as LLDPE) Copolymerization of ethylene and 1-butene by a gas phase method using titanium tetrachloride and triethylaluminum catalyst. I got it. (MF
R: 2.0 g / 10 min, density: 0.920 g / cm
³ ) (C2) Ultra-low density linear polyethylene (referred to as VLDPE) Obtained by copolymerizing ethylene and 1-butene by a gas phase method using titanium tetrachloride and a triethylaluminum catalyst. (MF
R: 1.0 g / 10 min, density: 0.900 g / cm
³ ) (C3) Low-density polyethylene (referred to as HPLDPE) Nisseki Lexron F31 (manufactured by Nippon Petrochemical Co., Ltd.) MF
R: 2 g / 10 min, density: 0.924 g / cm ^3.

(D) Nucleating agent (D1) Sorbitol type compound Shin Nippon Rika Co., Ltd. Gelol MD (referred to as DBS) (D2) Aromatic phosphate compound Asahi Denka Co., Ltd. MARK NA-10 (NA-10) Asahi Denka Co., Ltd. MARK NA-21 (referred to as NA-21)

Examples 1 to 7 As shown in Table 1, a propylene / ethylene random copolymer was added to the ethylene / α-olefin copolymer with the metallocene catalyst shown in the above-mentioned polymerization example, or other ethylene-based copolymers. 0.05% by weight of Irgafos 168 manufactured by Ciba-Geigy Co., Ltd. as an antioxidant, and Rikemar S-100A0.
15% by weight and 0.1% of Calcoal 80 manufactured by Kao Soap Co., Ltd.
% By weight, calcium stearate as acid absorber 0.0
8% by weight, 0.13% by weight of oleic acid amide as a release agent, and 0.3 parts by weight of a nucleating agent were added, and the mixture was uniformly mixed for about 30 seconds by a Henschel mixer, followed by injection molding. The results are shown in Table 1. Flexural modulus, Izod impact value, DuPont impact value, transparency, heat resistance, and odor are all good.

[0082]

[Table 1]

Example 8 60% by weight of (RPP) as the component A and (B
1) 40% by weight, 0.3 of (NA-21) as D component
The same operation as in Example 1 was carried out with the addition of parts by weight. The composition has MFR: 22 g / 10 min, flexural modulus: 6,9
00 kgf / cm ² , Izod impact strength: 19 kgf
・ Cm / cm ² , DuPont impact strength: 300 kgf ・ c
m or more, heat distortion temperature: 72 ° C., odor: good, and impact strength is excellent.

Example 9 80% by weight of (BPP) as the component A and (B
1) 20% by weight, 0.3 as component D (NA-21)
The same operation as in Example 1 was carried out with the addition of parts by weight. The composition has MFR: 38 g / 10 min, flexural modulus: 12,
300 kgf / cm ² , Izod impact strength: 12 kg
f · cm / cm ² , DuPont impact strength: 300 kgf ·
cm or more, heat distortion temperature: 103 ° C., odor: good, and a composition having a good balance between flexural modulus and impact strength.

Example 10 80% by weight of (HPP) as the component A and (B
1) 20% by weight, 0.3 as component D (NA-21)
The same operation as in Example 1 was carried out with the addition of parts by weight. The composition has MFR: 26 g / 10 min, flexural modulus: 15,
300 kgf / cm ² , heat distortion temperature: 115 ° C., odor:
The composition is good, has a large flexural modulus, and is excellent in heat resistance.

Comparative Example 1 The same test as in Example 1 was conducted using only a propylene / ethylene random copolymer as a resin component. The results are shown in Table 2.
It was shown to. The impact strength is poor.

Comparative Example 2 The same test as in Example 1 was conducted except that the nucleating agent was not added. The results are shown in Table 2. Inadequate transparency.

Comparative Example 3 The same test as in Example 1 was conducted except that (LLDPE) with Ziegler catalyst was used as the component (B). The results are shown in Table 2. Poor transparency.

Comparative Example 4 The same test as in Example 1 was conducted except that (VLDPE) with Ziegler catalyst was used as the component (B). The results are shown in Table 2. Although the flexural modulus is low, the transparency and Izod impact value are insufficient.

Comparative Example 5 As component (B), high pressure radical polymerization (HPLDP
The same test as in Example 1 was carried out except that E) was used.
The results are shown in Table 2. In particular, the DuPont impact strength is poor and the transparency is insufficient.

[0091]

[Table 2]

[0092]

The transparency and heat resistance of the propylene-based polymer can be improved by adding a specific ethylene / α-olefin copolymer or ethylene polymer having a narrow molecular weight distribution and compositional distribution to the propylene-based polymer and a nucleating agent. It becomes possible to provide a composition having a good balance of impact strength. Further, the container using the composition is excellent in transparency, heat resistance and impact resistance, and the resin component is little eluted.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C08L 23:08)

Claims (3)

(57) [Claims] 1. A propylene polymer (A) 98 to 50% by weight (B) (a) A transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton is contained as an essential component. Obtained by (co) polymerizing ethylene or ethylene and an α-olefin having 3 to 20 carbon atoms in the presence of a catalyst, (b) density 0.86 to 0.97 g / cm 3.
³ , (c) Melt flow rate 0.1-50g / 10
Min, (d) molecular weight distribution parameter Mw / Mn1.5-
5.0, (e) 2 to 50% by weight of an ethylene polymer or ethylene / α-olefin copolymer having a composition distribution parameter Cb of 1.2 or less, and (C) another ethylene-based polymer of 0 to 48% by weight. (D) Aromatic phosphate compound or sorbitol based on 100 parts by weight of the resin component
A polypropylene-based resin composition containing 0.01 to 2 parts by weight of a compound . 2. The polypropylene resin composition according to claim 1, wherein the other ethylene polymer (C) is at least one selected from the following polymers. [Ethylene-based polymer] (C1) Ethylene / α-olefin copolymer with a Ziegler catalyst having a density of 0.86 to 0.97 g / cm ³ (C2) Low-density polyethylene by high-pressure radical polymerization,
An ethylene / vinyl ester copolymer or a copolymer of ethylene and an α, β-unsaturated carboxylic acid or its derivative. 3. The polypropylene according to claim 1 or 2.
A container made of a resin composition.